British Military News, Technology & History

The British Army and the S-Tank

Thanks to Tim Morley for recommending this article and providing many of the sources for me.

-Tony

There have been few truly revolutionary tanks since their emergence in the trenches of the First World War. The evolution of the main battle tank was a slow affair with each new generation adding only a few more improvements over the previous but there have been some that have made the next step quite a radical one. Then there are the real oddities that appear every so often and one such tank is the Swedish Stridsvagn 103 (often abbreviated to Strv 103 or sometimes referred to as the S-Tank). At first glance there is little resemblance to what is considered to be a “tank” primarily because it lacks a turret.

Archer tank destroyer with fixed turret.

Turretless armoured fighting vehicles were not a new concept in the 1950s when work on the Strv 103 first began. The first ever operational tank, the British Mark I, carried its weapons in sponsons on the side of the vehicle. Later, as tanks progressed and became more and more integral to victory on the battlefield a series of tank destroyers were developed to counter them directly. These were primarily small tracked vehicles with a fixed or partially trainable main gun built in to the hull. So when the Swedish Army unveiled the Strv 103 to the world in the late 1950s describing it as a main battle tank many observers were puzzled. The Swedes argued that their new vehicle could be used like a main battle tank to hold a defensive line against invading Soviet tanks but offer a substantial increase in protection, be harder to detect and have excellent agility the latter of which was achieved by being the first tank fitted with a gas turbine engine.

The uniqueness of this vehicle extended beyond the exterior. The vehicle had a crew of just three when most turret tanks of the period had a crew of five. Two of the crew sat up front in the forward hull while a third sat at the rear of the vehicle and had an extra driving console for fleeing rearward. Armament for the tank was a bit more conventional however in that it was equipped with the outstanding British L7 105mm gun which at that time had become NATO’s standard tank gun equipping a large proportion of British, American and German tank designs. The barrel was lengthened compared to the standard gun on the Centurion and featured an autoloader which had a firing rate of 15rds/min. Elevating the gun was again a unique operation. The gun was fixed in to the hull so the tank used pneumatic suspension to raise or lower the front of the vehicle and subsequently the gun.

By 1964 the Swedish Army was introducing this seemingly revolutionary new kind of tank warfare and they began courting foreign interest. In the UK the new tank was met with both curiosity and suspicion. The British Army recognised the tank’s attributes quite quickly especially in the defensive role the Swedes had envisioned it would operate but questions were raised about how it would fare beyond that one role. Main battle tanks need to smash through enemy lines and take and hold territory. Also, holding a line involves relocating to new positions since once a tank fires it reveals its position. The British Army questioned the Strv 103’s ability to do this effectively because they suspected the gun could not fire on the move such as when fleeing from an ambush. In fairness this was a somewhat dubious criticism because in the early 1960s gun stabilisation on British and American tanks was quite poor and the chances of a British Army Centurion hitting a moving Soviet Army T-55 or T-62 on all but the flattest ground was low indeed. Nevertheless this was enough to keep British interest away from the Swedish tank until 1968 when the British and Swedish governments agreed to have two Strv 103s tested in the UK at the Bovington tank ranges. Two Strv 103As took part in the trials engaging a number of targets from both stationary and mobile positions. The trials also tested the tank across various forms of terrain as well as assessing its reliability.

The trials amazed the British observers. The Bovington testers reported back that the S-Tank (as the British referred to it finding its Swedish designation something of a mouthful) held numerous advantages over turreted tanks in their tests. The gun being built in to the hull improved stabilisation compared to a Centurion or Chieftain and also the S-Tank was harder to detect and engage quickly than the relatively mammoth-like Chieftain. When the trials were complete the British started to look at the S-Tank with even greater interest and enthusiasm but the trials at Bovington could only tell them so much. What they needed was to test the tank alongside the standard vehicles of the British Army in an operational theatre and compare the two. To that end they began putting together a plan to conduct exercises with British crews operating a number of vehicles alongside and even against the British Army of the Rhine (BAOR)’s Chieftains. Here the tank would be tested in terrain and operational conditions exactly like those they would face in the event of a Soviet thrust from East Germany.

The British Army reasoned that it would need around ten vehicles to properly assess the S-Tank in the field looking at things such as reliability and effectiveness in combined operations. This was a large number for a trial and required support from the Swedish Army to provide the vehicles. The Swedish decided to support the request believing that a successful outcome of the trials might encourage both a highly sought after export sale as well as providing a stamp of approval of the design from the British which could improve the prestige of Swedish engineering.

S-Tank on British transporter (Swedish Army)

The exercise was scheduled for the summer of 1973. In early 1973 a number of crews from the 2nd Royal Tank Regiment (RTR) were selected for the program and sent to Sweden for training on how to operate the new type. It is important to note that the British crews were primarily trained in the actual operation of the vehicle with tactics remaining primarily British. Upon completion of the training the tanks and their newly trained crews made their way to West Germany for the crews to familiarise themselves with operating the vehicle in the terrain where they would be conducting the exercise in July 1973. With so much invested in the exercise the Swedish sent their own observation mission. The exercise saw two units facing one another; one known as OPFOR with a mix of Chieftains and S-Tanks while BLUFOR operated with Chieftains only. The trials were carried out over a period of nine days and saw the S-Tank operate in a number of scenarios alongside and against Chieftains, Scorpion light tanks and FV432 armoured personnel carriers.

The exercise progressed well and the British crews praised the reliability of the S-Tank which never fell below 90% (there was never a point where less than nine of the ten S-Tanks were not available). By comparison the Chieftains had an appallingly low serviceability rate to the point where a number of OPFOR’s Chieftain’s had to be transferred to BLUFOR to replace broken down ones and keep the exercise going. However, the enthusiasm the British Army had shown after Bovington for the S-Tank was now dropping off. The 2nd RTR crews didn’t seem to perform any better than their Cheiftain comrades when it came down to engaging the enemy. They admitted that there were times that the S-Tank was superior to the Chieftain namely when operating defensively in confined spaces however the tests also showed that the S-Tank had to expose more of its hull when firing over embankments or down from hilltops. Also the fixed gun left the tank vulnerable in an ambush since the whole vehicle had to turn and face an attacker increasing its vulnerability whereas a Chieftain could both retreat and defend itself simultaneously. In the end the British Army concluded that the advantages of the S-Tank were not enough to warrant an acquisition and interest was suspended.

The Swedish were not happy. The Swedish observation mission published a damning report on the exercise effectively dismissing the results and heavily criticising the British tank crews and commanders. Among other things the Swedes criticised the conduct of British crews as being very unprofessional and significantly below the average Swedish crew which resulted in a very poor showing of the S-Tank. The Swedes also criticised the fact that British gunners could not engage a target without the tank commander’s order. In the Swedish Army they stated that the S-Tank had a much higher number of firings because they operated on the principle of whomever sees the target first can fire. The incredible report even goes as far as to state that British tank crew’s eyesight was rather poor and not properly tested like Swedish crews.

In terms of tactics the Swedes were aghast at how thinly the British tanks were spread across a defensible line. They argued that to effectively hold an area of territory the number of tanks that were being used needed to be deployed under half a kilometre but British crews deployed them as far along as 800m. This criticism reflects how different British and Swedish operational needs were. Swedish tank units had a high number of vehicles to defend a relatively small proportion of land. British units had a similar number of vehicles but had to defend a much wider line on more open terrain against a numerically superior force. The wide line was needed to limit Soviet tanks’ ability to break through gaps and surround British units. It was this fact alone that actually dictated the design of the Chieftain which was bigger and more powerful than the vast majority of Soviet tanks allowing it to be able to confidently engage a numerically superior force. Just how good the Chieftain was at this role was dramatically displayed in 1991 when a Kuwaiti Chieftain held a street against a number of Iraqi T-55s and T-72s and was only destroyed when the crew abandoned the vehicle after it ran out of ammunition.

All these criticisms proved first and foremost was that the S-Tank was designed for the Swedish Army and not the British Army. The S-Tank or (Strv 103) was a tank for the Swedish theatre where the main concern was defence in heavily wooded terrain where the tank’s low profile made it easy to hide and limited an enemy’s movements. On the plains of West Germany however those attributes became more questionable and given that the Royal Tank Regiments of the British Army suffered at the hands of the Germans in World War II because of equipment that wasn’t up to the task the British elected to stick with the Chieftain leaving the “British Army S-Tank” concept as something of a brief flirtation only.

You can view some translated sections of the Swedish report and some fascinating photographs of the exercise by clicking here

Really interesting. I think you make some good points, it was designed for a different army and terrain, and therefore won’t perform in the same way. I always considered fixed turret tanks as vulnerable and easy pray for the more versatile rotating turrets tanks. A good discussion Tony.

Interestingly, when I put this on Facebook someone messaged me with a link to a wiki site that showed a British design from around the same period that was actually similar in configuration but was intended as a tank destroyer. It was decided that the Chieftain was enough of a tank destroyer and production didn’t go ahead.

glad to find out this incredible blog. So I’m one of the admins at http://www.military.database.de. Specially this report about the S-Tanks will close a gap. So maybe it is worth for you to have a look on this link here:

But, in the Gulf wars, it fared not too well. Both irakis and iranians agreed that the T-72 was better than the Chieftain, basically iranians rated the Chieftain less than the M-60.

A proof is that, irakis captured many Chieftains but basically did not use them and sent them to Jordanians and anti-iranians kurds instead. Even when british offered them, irakis responsed that they simply did not need them. If the Chieftain was really a great tank, irakis should take as many as they could get. (see the book ‘Saddam generals’)

Regardless of the soundness of the design, the S-tank, despite the ‘naval’ powerplant CODAG, was very reliable. The Chieftain, OTOH, was unforgible for its mechanical unreliability and low power ratio.

As defensive (like in Kuwait) i don’t see any reason to rate an S-tank less than a turreted tank. The problem is, in fact, if a turretless tank is able to fight in offensive, not surely in defensive role.

Actually, the Stridsvagn 103 was designed to be used in a similar environment to that in the northern parts of Germany. The stridsvagn 103 was first introduced to the southern most parts of Sweden, which has a terrain similar to that of the northern parts of Germany. The other placement for the Stridsvagn 103 was in the far north where you also can find long range engagement and little cover.

I received training on the Strv 103 and anupgraded Centurion. The were quite different and handled differently. The 103, if driven aggressively was much faster on target and had the second shot fired quicker than it was possible to do with the Centurion. Thanks to this it was moving again after a very short time.
The real weaknesses were two: the tracks were shorter so it required more driver-skils not to get stuck. The other drawback was that the gastubine needed to rev-up considerably to deliver the power needed for an accelleration which gave protective speeds. The last version with a Detroit-diesel was an immense improvement in this respect.